发明名称 Terminal apparatus having a function for preventing unnecessary line connection
摘要 Terminal apparatus is disclosed which alternatively connects a data terminal apparatus by a first switching unit to a line. The terminal apparatus includes a telephone, on-hook transmit circuit, and second switching unit for connecting the telephone set and on-hook transmit circuit alternatively to the line via the first switching unit. The on-hook transmit circuit includes a unit responsive to an on-hook transmit operation to switch the second switching unit to an on-hook transmit circuit, unit responsive to a dial signal transmit operation to transmit the dial signal to the line, direct current closing unit which continues to be connected to the line with the second switching unit switched to the on-hook transmit circuit, line release detection unit and control unit. The line release detection unit generates a line release detection signal when the line release detection unit detects the line as being released. Upon the generation of the line release detection signal, the control unit supplies a switching control signal to the second switching unit to switch the second switching unit from an on-hook transmit circuit to a telephone set.
申请公布号 US4939777(A) 申请公布日期 1990.07.03
申请号 US19890323929 申请日期 1989.03.15
申请人 KABUSHIKI KAISHA TOSHIBA 发明人 OKA, TOSHO
分类号 H04M1/60;H04M1/2745;H04M11/06 主分类号 H04M1/60
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